FARGO , North Dakota -LRB- CNN -RRB- -- Forecasters issued flash flood warnings for Bismarck and surrounding areas Wednesday , as volunteers rushed to fill sandbags ahead of expected record floods in the flat state of North Dakota .

Explosives are set off in the Missouri River on Wednesday to break up ice jams .

Areas of three counties -- Morton , Emmons and Burleigh , which includes the North Dakota capital of Bismarck -- were under a flash flood warning until 12:30 p.m. CT -LRB- 1:30 p.m. ET -RRB- , the National Weather Service said .

In an effort to alleviate the flooding , demolition crews blew up an ice jam Wednesday evening south of Bismarck , according to CNN affiliate KXMB .

Mayor John Warford said that water appeared to be moving more freely in the Missouri River after the explosives were set off , KXMB reported . The plan is make sure water continues flow through the river channel and not spread out over land . Ice jams in rivers have been a major factor in the flooding there .

Most of the state , which endured a particularly harsh winter , remained under a flood warning Wednesday , with forecasters predicting possibly record flood levels on several rivers .

Snow , which continued to fall Wednesday , complicated preparations , city officials said . `` I woke up this morning and looked outside , I guess I thought of the same thing everybody else did . ... -LSB- What -RSB- came to mind is what a revolting development this is , '' said Mark Voxland , the mayor of Moorhead , Minnesota , a city just outside of Fargo . Watch flooded fields of snow ''

More than 1,000 people were evacuated from an area near Bismarck on Tuesday night as the Missouri River flooded , Rick Robinson of the North Dakota Department of Emergency Services said Wednesday . See a map of the affected area ''

Emergency officials said they were particularly concerned about the Red River , which snakes through eastern portions of North and South Dakota and western Minnesota .

The river is expected to crest between 39 and 41 feet in Fargo on Friday , according to Cecily Fong of the North Dakota Department of Emergency Services . The record for the Red River at Fargo was set in 1897 at 40.1 feet , according to Pat Slattery of the National Oceanic and Atmospheric Administration .

The threat of flooding prompted authorities to ask for volunteers to fill sandbags either to build temporary dikes or to bolster existing ones . In some areas , even at 3:30 a.m. , hundreds of volunteers packed into individual sandbagging centers , an organizer said . See images of flooding , preparation ''

`` There have been so many volunteers that we had to turn people away , '' said Ryan McEwan , a supervisor at one volunteer coordinating center . `` It is very busy . They are filling sandbags as fast as they can . ''

As of late Tuesday , Fargo residents and out-of-town volunteers had filled more than 1 million sandbags out of the needed 2 million . Fargo Deputy Mayor Tim Mahoney said he hoped that goal would be met by Thursday .

Fargo 's mayor , Dennis Walaker , said Wednesday that his city was about 95 percent prepared for the flooding , which is expected later in the week .

`` I went and looked at the dikes this morning , and they 're significant , absolutely significant , '' he said in a briefing Wednesday morning .

However , he said , `` We have some areas we need to shore up . ''

Just south of Fargo , authorities said they had rescued several people in Oxbow , a town of about 238 people , after a residential dike gave way .

In some places , water had reached halfway up residents ' basement stairs , and in others , it had reached the main level of homes , Sgt. Gail Wichmann said .

CNN 's Chris Welch contributed to this report .

@highlight

NEW : Ice jam in Missouri River blown up , CNN affiliate KXMB reports

@highlight

Bismarck , surrounding areas threatened ; snow complicates preparations

@highlight

Fargo halfway to 2 million-sandbag goal , which may be met Thursday

@highlight

South of Fargo , town residents rescued after residential dike gives way